God mode

Berserk mode

Disable God mode

Press Start to pause game play, then hold L R and press A2, B, A, B4.

Level skip

In single player games, press Start to pause game play, then hold L R and press A, B, A2, B3, A.

Advance ten levels

In single player games, press Start to pause game play, then hold L R and press A, B, A2, B2, A2. You will advance ten levels, depending on the current level. Note that there are only twenty four maps in single player games; therefore this code will not work when starting from maps higher than 14, "Halls Of The Damned".

Radiation suit

Tower Of Babel level

Pause the game, then hold L R and press A, B, A, B, A, B, B, A.

All weapons, items and keys

Pause the game, then hold L R and press A, B, B, A, A, A, A, A.

Hidden Military Base area

You can find this area in the Toxic Refinery Episode 1, Level 3. Complete the first half of the level before you enter the blue door, then go back to the starting point. Look inside the pool of radioactive waste and you should see a platform if you flipped all the switches in the first half. Walk across the platform towards the wall it leads to. The wall will open and you will have to defeat a series of enemies. Explore the secret area more and you should find an exit door. Enter it and flip the switch the stats will not appear. You will now be an area called the Military Base.
Note: This area can be very difficult.